Tube clamp



Aug- 5, 1 4 R. R. HARRISON TUBE CLAMP Original Filed Oct. 10, 19416(WELD) INVENTOR ROBERT R. HARRISON A Tram/g r Patented Aug. 5, 1947TUBE CLAMP Robert R. Harrison, Pacific Palisades, Calif., as-

signor to Bendix Aviation Corporation, South Bend, Ind., a corporationof Delaware Original application Oct ober 10, 1941, Serial No. Dividedand this application October 4, 1945, Serial No. 620,208

7 Claims.

This invention relates to tube clamps and more particularly to tubeclamps which are provided with means to electrically ground any tube orconduit held in the clamp. The present application is a division of myco-pending application Serial No. 414,417, filed October 10, 1941, andentitled Tube clamps. This application has issued as Patent No.2,399,183, dated April 30, 1946.

One object of the invention is to provide a tube clamp having anelectrical grounding strip provided with a curved portion to accommodatevibration well within the elastic. limit of the strip.

Another object of the invention is to provide a tube clamp with anelectrical grounding strip which is rigidly aligned with the metal loopforming the main element of the clamp.

Other objects and advantages of the invention will be apparent in thefollowing description and claims taken in connection with theaccompanying drawing in which:

Figure 1 is an isometric view of a tube clamp embodying the invention;and

Figure 2 is an isometric View of a portion of the strip of the loop ofFigure 1, showing the grounding strip welded to the metal loop, andshowing the cushion in dotted outline.

For present purposes, it will be stated that the clamps are used to holdconduits to any structural member of the vehicle in which they aremounted. They are particularly adapted for use in airplanes, and forthis purpose a cushion element must be provided to prevent injury to theclamped tube due to the intense vibrations found in airplanes. However,it has been found that static charges accumulate on conduits held in aninsulating material such as is commonly employed as the cushion element,and electrical grounding strips are employed to remove the staticcharges, which present a fire hazard, as well as an interference toradio operation, when they discharge across an air gap.

The clamp of Fig. 1 comprises a metal strip 40 of aluminum, or wheregreat strength is required, of stainless steel, although it may be madeof any suitable electrically conductive material. The metal strip 49 isbent to a rounded shape so as to form a loop to encircle any tube orconduit which may be held therein. One end 41 of the strip 48 is bent atright angles to the body of the strip, so as to be parallel with theother end and permit a screw to be passed through holes 49 and 53 in theends 4'! and 5! to secure the clamp as a whole to any member. The clampis provided with a cushion 42, which is preferably of a resilientmaterial such as the commonly available synthetic rubber-like materials.which are resistant to oil and gasoline. Since such cushions are usuallyinsulators, a grounding strip 44 is secured to the metal loop 49 andoverlies the cushion 42 so as to electrically ground any conduit to themetal of the clamp loop 40.

The loop strips 49 are first formed in a fiat position (Fig. 2). Thegrounding strip 44 is welded to the loop strip 40 by a spot weld 46,after which the cushion 42 is bonded to the strips 40 and 44 by methodswell known to the art. The outer end of the strip 44 is then bentupwardly and over to overlie a portion of cushion 42 as shown in Fig. 1.Thereafter the metal strip 40 is bent to the shape shown in Fig. 1.

The construction described has the advantage over prior art structuresthat the long bend in the grounding strip 44 at the region 48 which isin excess of gives a suflicient are or curvature in the strip 44 so asto accommodate any reversals of stress without bending the strip in theregion 48 beyond the elastic limit of the material. This insures freedomfrom fatigue cracks in the grounding strip 44 and insures that thegrounding strip will always overlie the cushion 42. The reversals ofstress in the grounding strip 44 may be caused by vibration in servicebetween the clamp and the tube or conduit supported thereby.

Reversals of stress are further reduced or eliminated in accordance withthe invention by the fact that the cushion. is vulcanized or bonded tothe clamp strip 40.

As has been previously mentioned, the of the grounding strip 44 to thestrip 40 that it will not swivel about its point of ment and therebywork out of contact conduit engaged by the clamp.

Although the invention has been explained by showing and describing indetail a specific embodiment thereof, various changes from the specificconstruction shown will be apparent to those skilled in the art, and theinvention is therefore to be limited only to the extent set forth in theappended claims.

I claim:

1. In a line grounding clip embodying a metallic supporting strap, and acushioned seat carried by said strap and extending along the innerperiphery thereof; an electrically conductive strip bent intermediateits ends and positioned astride an end of said cushioned seat with oneof its end portions extending between said seat and said strap and withits other end portion overlying the outer face of said seat forinterposition between said seat and a conduit imposed on the weldinginsures attachwith any latter to effect electrical connection betweensaid conduit and said strap around the terminus of said cushioned seat.

2. A tube clamp comprising a loop of metal, a cushion element overlyinga portion of the inner face thereof, and an electrical conductor securedto the loop and overlying a portion of the-cushion, said conductor beingformed with a pronounced curved portion with at least a 170 curvetherein to accommodate stresses.

3. In a line grounding clip embodying a metallic supporting strap and acushioned seat carried by said strap and extending along the innerperiphery thereof; an electrically conductive strip bent intermediateits ends and positioned astride an end of said cushioned seat with oneof its end portions extending between said seat and said strap and withits other end portion overlying the outer face of said seat forinterposition between said seat and a conduit imposed on the latter toeffect electrical connection between said conduit and said strap aroundthe terminus of said cushioned seat, and means effecting a positiveconnection between said electrically conductive strip and saidsupporting strap.

4. The structure called for in claim 3 in which the connection betweenthe strip and strap is located beneath an end portion of the cushionedseat to be covered by the latter.

5. In a line grounding clip, a metallic line supporting strap, acushioned seat lining said strap, an electrically conductive striphaving a portion overlying said cushioned seat and disposed to contact aconduit seated on said seat and having another portion overlying an endof said cushion seat and extending between the latter and said strap,whereby said portions of said strip will be pressed into said cushion onclamping said strap around a conduit, with a positive connection betweenone of the named portions of said strip and said supporting strap.

6. A tube clamp comprising a loop of metal, a conductor strip having aportion welded to said metal loop, and a cushion overlying a portion ofsaid conductor strip and a portion of said metal loop, said conductingstrip being bent back upon itself to overlie a portion of said cushion.

'7. Atube clamp comprising a loop of metal, a conductor strip having aportion welded to said metal loop, and a cushion overlying the portionof said conductor strip welded to said metal loop and also overlying aportion of said metal loop, said conducting strip being bent back uponitself to overlie a portion of said cushion.

ROBERT R. HARRISON.

